Answer:
Total cost = 16
Step-by-step explanation:
In the equation of cost, we can see that each rose costs 3 and each petunia costs 2.5.
To find the total cost of two roses and four petunias, we can use the values r = 2 and p = 4 in the equation given, so:
Total cost = 3r + 2.5p = 3*2 + 2.5*4 = 6 + 10 = 16
So the total cost of two roses and four petunias is 16.
